Trouble grouping .375 H&H

[sestoppelman]

The gun will do it but I don't. I did at SAAM, not in the field. I like to get as close as I can. Most of the fun is in the stalk.

I think the longest shot I have taken with my .375 is maybe just over 200 yards over open ground from a sit. Red Lechwe in Botswana. Back when I was probably in my best shooting years. Shooting NRA High Power all the time from position. Anything much over 200-250 is a stretch for most from field positions while hunting.

 

[fourfive8]

Well, if you got "clover leafs" at first then suddenly it won't shoot with identical load... seems like something other than the load or ammo. However, I am still somewhat confused about the first part of your post. IF you are confident in the consistency of your loads then it is going to be the gun or the scope. There are no other choices. If that is case, no use in tweaking loads at this time.

I'd start with the rifle. Either DIY or get a smith, who knows how to pillar bed it. Then shoot it with the same load/ammo that was shooting well before. Also, visually check the crown with a magnifying glass in good light. Now that's an easy check! Correct bedding might help and will not hurt.

If it is still acting badly, replace the scope and make sure the mounts are secure.

If it is still acting badly, try another couple of generic, standard 375 HH loads/bullets that are known to shoot well.

If it is still acting badly, start an investigation into who may have bent the barrel.... because that's about all, with the exception of developing a flinch, there is left to blame.

 

[bruce moulds]

parallax adjustment in the scope?
bruce.

 

[bruce moulds]

I think the longest shot I have taken with my .375 is maybe just over 200 yards over open ground from a sit. Red Lechwe in Botswana. Back when I was probably in my best shooting years. Shooting NRA High Power all the time from position. Anything much over 200-250 is a stretch for most from field positions while hunting.

well said.
bruce.

 

[Gert Odendaal]

I started reloading 300gr barnes for it to get a better group and I got a group to clover leaf at 100yds. I used that load to make more the same way and went out and shot.
During this process, something changed in /onto/with your .375 caliber rifle..the batch of powder you used is it from the same "clover leaf " container you used to do the clover leaf reloading ?
You did not change anything to your rifle in that time? Did you use exactly the same set up to shoot the "more of the similar loads" from a bench ? Sledge? maybe something changed in the environment you were shooting on like a rest, or the felt recoil was starting to get to you and flinching started in??
Could you have adjust the scope without knowing it through bumping it against an object...
If this is not due to your scope ....it must be in your powder you used or the powder scale measuring changed ..

 

[colorado]

That is exactly why Colorado has a .500 Jeffery to shoot out accurately to 250 m up to 350 meters with his .500 Jeffery rifle

Furthest shot so far a cow elk at 225 yards. Sitting with a sling, she didn't get up lol Most of the time I like still hunting in the deep timber. Fast shots at bull elk running through the trees. The 500 Jeffery is great for that. Hope to do that again this fall, been awhile.

 

[Gert Odendaal]

t shot so far a cow elk at 225 yards. She didn't get up lol

Colorado, gentleman, might I point it out to you,it does not look like it but according to the technical/ ballistic l inclined your .500 Jeffery has much more up it`s muzzle...I really would like to see what you can achieve at longer ranges with your .500 Jeffery...what grain bullet weight do you think you can go down to but still manage to stabilise the bullet without fishtailing ???

 

[PHOENIX PHIL]

@In_die_bos,

You've received a lot of good information here and I won't bother to repeat it. I will say when I started load dev't on my .375 M70, I found it didn't care that much for Varget or it's virtual twin RL15. Many 375 owners have found good loads with these powders.

What I found worked very well with 300gr pills is IMR4350. It works well with North Fork bonded cores, Swift A-Frames and the Barnes TSX.

But it was with the Barnes TSX I found they are sensitive to copper fouling. If you're going to use these, I recommend you clean your barrel very thoroughly. As copper free as you can get within reason. Once you do this, retry your Barnes load that you had some success with early on. And also of course once you're certain screws are tight and you don't have a broken scope.

What I have found in my 375 and other rifles is that once the copper builds up enough, accuracy will drop off and drop off fast with subsequent shots. Clean the barrel again and the accuracy will return. I am not the only one in this world that has seen this. I picked up that this might be the problem for me after reading a number of reports of this issue with Barnes.

As you're shooting these, take time to inspect the crown and that end of the barrel that you can see into. What you're looking for is that copper build up coming off the bullets. If your experience is similar to mine, you will notice your barrel there going from black/grey to the same color as your bullets. While doing this of course keep track of how many rounds you've put down range.

For my rifle, somewhere around 8-10 rounds is when the accuracy started to drop off. This issue is I believe a function of the copper Barnes uses as well as the barrel. A tighter barrel and the build up will happen sooner and you'll see the accuracy problem that much sooner. A looser barrel and you may never see the issue as you clean the barrel before it ever becomes a problem.

 

[Gert Odendaal]

@In_die_bos,

You've received a lot of good information here and I won't bother to repeat it. I will say when I started load dev't on my .375 M70, I found it didn't care that much for Varget or it's virtual twin RL15. Many 375 owners have found good loads with these powders.

What I found worked very well with 300gr pills is IMR4350. It works well with North Fork bonded cores, Swift A-Frames and the Barnes TSX.

But it was with the Barnes TSX I found they are sensitive to copper fouling. If you're going to use these, I recommend you clean your barrel very thoroughly. As copper free as you can get within reason. Once you do this, retry your Barnes load that you had some success with early on. And also of course once you're certain screws are tight and you don't have a broken scope.

What I have found in my 375 and other rifles is that once the copper builds up enough, accuracy will drop off and drop off fast with subsequent shots. Clean the barrel again and the accuracy will return. I am not the only one in this world that has seen this. I picked up that this might be the problem for me after reading a number of reports of this issue with Barnes.

As you're shooting these, take time to inspect the crown and that end of the barrel that you can see into. What you're looking for is that copper build up coming off the bullets. If your experience is similar to mine, you will notice your barrel there going from black/grey to the same color as your bullets. While doing this of course keep track of how many rounds you've put down range.

For my rifle, somewhere around 8-10 rounds is when the accuracy started to drop off. This issue is I believe a function of the copper Barnes uses as well as the barrel. A tighter barrel and the build up will happen sooner and you'll see the accuracy problem that much sooner. A looser barrel and you may never see the issue as you clean the barrel before it ever becomes a problem.

Phil, I think you have the correct answer to his problem, for sure....I was not aware that Barnes bullets are prone to copper fouling in such an extend that it can influence the accuracy of a rifle that much??? Are there other hunters/shooters who experience the same scenario???

 

[Opposite Pole]

8-10 rounds sounds extreme, perhaps the barrel is new and needs to be run-in/deburred? Most extreme case of sudden accuracy drop due to fouling I’ve seen was on my CZ 17HMR, after about 50 rounds it’d start shooting all over the place. Pulling a snake through twice was enough to get it back to normal. The first pull was actually pretty tight and hard. But 8-10 rounds seems abnormal and not practical.

 

[2400]

Hello all,

I have a Winchester Model 70 in .375

Guidance or ideas on what to do would be great. Thank you to all in advance!

A lot more info would be helpful, then you might get some good suggestions that would help you solve the problems you're having.

Be great if he came back with more info....

Sestoppelman I agree with you. I've seen this on a lot of forums over the years ask a vague question and never add anymore to it.

I have 2 Win model 70's in 375 H&H and have some ideas that might help but some more info would be nice.

 

[colorado]

Colorado, gentleman, might I point it out to you,it does not look like it but according to the technical/ ballistic l inclined your .500 Jeffery has much more up it`s muzzle...I really would like to see what you can achieve at longer ranges with your .500 Jeffery...what grain bullet weight do you think you can go down to but still manage to stabilise the bullet without fishtailing ???

Not sure, but I really think 570g is the sweet spot. I do think one could get close to 2700 fps with the 535g bullets but it's really not a long distance round. I just use mine to hunt everything, so if and when I finally get to Africa it will be as familiar to me as the 270 I hunted 40 years with. If I ever go back for a second Alaskan brown bear, I'll have a synthetic stock put on it and take it. Really like the rifle.

 

[Gert Odendaal]

Colorado, it is great to have so much appreciation/love for a caliber not frequently shoot by the average hunter with such confidence you have in your .500 Jeffery . I am fortunate to have the same feelings towards my 404 Jeffery, it is fitting me like a glove...I really do not need other caliber rifles at all..since I do have other rifles it is a nice to have scenario.. when we are allowed moving around again I am getting close and personal with my 404 Jeffery on a shooting range near me again....just to strengthen my bond with this magnificent caliber..

 

[Forrest Halley]

I am fortunate to have the same feelings towards my 404 Jeffery, it is fitting me like a glove...I really do not need other caliber rifles at all..since I do have other rifles it is a nice to have scenario.. when we are allowed moving around again I am getting close and personal with my 404 Jeffery on a shooting range near me again....just to strengthen my bond with this magnificent caliber..

Chugs Koolaid...
Begins chant while circling bon fire...
".404! Wonder bore! .404! Thunder bore! Who could...who could ever ask for more? All I need's a .404! Shoot and shoot and shoot some more! Thunder bore! Wonder bore! .404! .404!"
Repeats steps above until all present are thoroughly indoctrinated. Obtains contact info from attendees and mails out chamber reamers as Christmas presents.

 

[Ridgewalker]

How about a status report?

 

[In_die_bos]

To all who have commented, thank you. I havent been able to get to a computer for a bit....the scope is a leupold VX-3 2.5-8x36mm. I assumed a good scope. I have used loads of 70.5, 71, 71.5, and 72 grains of reloader 15 after doing research because this is my first time reloading. My remington 700 in .270 is a tack driver with factory ammo at 100. So this is all new to me. I have also shot probably 30 rounds of factory ammo all different weights and makes through before I started the reloading. My brass came from those factory ammo shots. So I have nosler, barnes, federal, remington but when I shot my reloads I tried to shoot all the brass of the same type together to minimize differences. All the other loads I tried were bigger than what I am getting now grouping wise. Once again thank you for all the responses and sorry for the long wait...

 

[In_die_bos]

Goin back to the range tomorrow, shooting off sandbags and testing a few other suggestions from here.

 

[Ridgewalker]

In_die_bos, I load 72.0 R15, WLRM, 300 Barnes TSX in Barnes or Norma brass for a screaming 2,665 fps. I plan to back it off another grain to 71.0 the next time I load it. In my MRC 24” barrel it will shoot 3 into 1/2” at 100 meters consistently.

You might back down to 68.0 or 69.0. I would only try 3 round groups to start with. If you have a 200 yard range or more, you might try a ladder test. 1 round at each grain weight in 1/2 grain increments. Watch it closely, or better go down and check marking each shot. Find three or four of adjacent grains which group closest. I pick the middle grains and shoot a 3 round group.
Something else I do between groups is to pull a boresnake through and cool the barrel.
My COAL is 3.570”.
Best of luck finding your sweet spot!

 

[8x68]

Couple of things.
Don't forget it's a hunting rifle not an F-Class rifle so groups of 1-2" are OK if staying within 300yds (my experience with my 375H&H).
Are you allowing proper cool down between strings? If the barrel hasn't been "free floated" there may be contact spots in the barrel channel that may be playing a role in affecting your accuracy.
Something to try. From a cold barrel run a piece of paper along the barrel channel as far as it will go. Can you get as far as chamber? Do the same for a hot barrel. Does the piece of paper bind?
I have done this with a number of factory rifles that have a similar issue to yours. Sometimes its the scope but more often than not, as long as your using the same reloading components & regimen, it's a "spot along the channel. Granted I have also had it go the other way where the rifle shot well with "speed bumps" along the channel.

 

[gillettehunter]

8-10 rounds sounds extreme, perhaps the barrel is new and needs to be run-in/deburred? Most extreme case of sudden accuracy drop due to fouling I’ve seen was on my CZ 17HMR, after about 50 rounds it’d start shooting all over the place. Pulling a snake through twice was enough to get it back to normal. The first pull was actually pretty tight and hard. But 8-10 rounds seems abnormal and not practical.

I had a .300 WSM in a Tika T-3 that did that too. Clean it good and it was a great 1/2 MOA rifle for about 10 rds. Then they quickly went to about 2 1/2 MOA. Quite the difference. Always wondered if it was the barrel as I didn't have that problem with Barnes bullets in other rifles that I reload for. That was the best I could come up with. There was no doubt that was the issue with that rifle as I saw it happen numerous times.
Bruce